Receiving device and method, transmitting device and method, and program

ABSTRACT

The present disclosure provides a receiving device including, a receiver that receives AV content, a detector, an acquirer, a tentative reservation registering part, and a definitive reservation registering part.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.13/452,376, filed Apr. 20, 2012, which claims the benefit of priority ofProvisional Application Ser. No. 61/480,033, filed Apr. 28, 2011, theentire contents of which is incorporated herein by reference.

BACKGROUND

The present technique relates to receiving devices and methods,transmitting devices and methods, and programs, and particularly toreceiving device and method, transmitting device and method, and programthat enable assured download reservation of AV content.

In recent years, due to dissemination of digital broadcasting, receptionof multiple channels and high-definition television broadcasting hasbecome general.

Meanwhile, technique studying and system formulation for enabling notonly normal television broadcasting but also more advanced broadcastingservice required by viewers by utilizing the band that can be used inthe digital broadcasting are being carried out.

Functions required by viewers include on-demand viewing, which allows AVcontent to be viewed whenever a viewer wants to view it. However, it isconsidered difficult to realize the on-demand viewing in notbroadcasting of bidirectional transmission but broadcasting ofunidirectional transmission.

So, in order to enable the on-demand viewing in the broadcasting ofunidirectional transmission, studies are being made on the NRT servicein which broadcast AV content is temporarily recorded in a storage andthereafter reproduced thereof on the premise that the receiving deviceholds the high-capacity storage (see Japanese Patent Laid-open No.2011-41242, hereinafter referred to as Patent Document 1).

The NRT (Non Real Time) service is not premised on viewing in real time.In this service, there is no need to view AV content in synchronizationwith the broadcast time of the AV content and AV content is transmittedas data by a broadcast signal.

Specifically, in the NRT service, completion of recording (download) ina shorter time is possible if the transmission band of a signal with abroadcast wave is wider for example, differently from past recordingreservation of AV content of a broadcast show. Or, download is completedin a longer time if the transmission band of a signal by a broadcastwave is narrower for example.

SUMMARY

In the NRT service of the past, in the case of reserving download of AVcontent, information that is called NRT-IT (NRT Information Table) andrelates to download of AV content transmitted in non-real time needs tobe acquired in advance. In the NRT-IT, a list of AV content for whichdownload reservation is possible is described. From the list, desired AVcontent is selected.

The NRT-IT is periodically transmitted together with AV content.However, if the NRT-IT held by the receiving device is old, even AVcontent for which download reservation is possible essentially cannot bereserved and the download reservation must be awaited until the NRT-ITis updated. As a result, possibly the opportunity for the downloadreservation of the AV content is lost.

The present technique is made in view of such circumstances and is toenable assured download reservation of AV content and widening of theopportunity for download reservation.

A receiving device of one embodiment of the present technique includes areceiver that receives AV content, a detector that detects triggerinformation that is transmitted together with the AV content to bereceived and relates to control of an application program for being runin conjunction with the AV content, and an acquirer that acquires anapplication program for allowing selection of AV content for whichdownload reservation is possible and that is transmitted in non-realtime, based on the detected trigger information. The receiving devicefurther includes a tentative reservation registering part that registersAV content selected based on the acquired application program astentative reservation, and a definitive reservation registering partthat registers the tentatively reserved AV content as definitivereservation if an identifier of AV content for which downloadreservation is possible, included in download information that isperiodically transmitted together with the AV content and relates todownload of AV content transmitted in non-real time, is identical to anidentifier of the tentatively reserved AV content.

The tentative reservation registering part registers selected AV contentas tentative reservation if the download information is not recorded.

The application program is content for allowing selection of AV contentfor which download reservation is possible and that is transmitted innon-real time based on a list.

The receiving device further includes a controller that controlsacquisition or activation of the application program or stop of theapplication program that is running, in accordance with a commandindicated by the detected trigger information.

The receiving device may be an independent device or may be an internalblock configuring one device.

A receiving method or a program of one embodiment of the presenttechnique is a method or a program corresponding to the above-describedreceiving device of one embodiment of the present technique.

In the receiving device and method and the program of one embodiment ofthe present technique, AV content is received, and trigger informationthat is transmitted together with the AV content to be received andrelates to control of an application program for being run inconjunction with the AV content is detected. Based on the detectedtrigger information, an application program for allowing selection of AVcontent for which download reservation is possible and that istransmitted in non-real time is acquired. Furthermore, AV contentselected based on the acquired application program is registered astentative reservation. In addition, the tentatively reserved AV contentis registered as definitive reservation if the identifier of AV contentfor which download reservation is possible, included in downloadinformation that is periodically transmitted together with the AVcontent and relates to download of AV content transmitted in non-realtime, is identical to the identifier of the tentatively reserved AVcontent.

A transmitting device of one embodiment of the present techniqueincludes a trigger information generator that generates triggerinformation relating to control of an application program run inconjunction with AV content in a receiving device, a transmitter thattransmits the generated trigger information together with the AVcontent, and a download information generator that generates downloadinformation relating to download of the AV content transmitted innon-real time. The transmitter periodically transmits the generateddownload information together with the AV content.

At least one of commands to control acquisition or activation of anapplication program for allowing selection of AV content for whichdownload reservation is possible and that is transmitted in non-realtime or stop of the application program that is running is included in acommand indicated by the trigger information.

The transmitter multiplexes the trigger information into a transportstream corresponding to the AV content and transmits the triggerinformation.

The transmitter stores the trigger information in an adaptation field ofa packet configuring a transport stream corresponding to the AV contentand transmits the trigger information.

The transmitting device may be an independent device or may be aninternal block configuring one device.

A transmitting method or a program of one embodiment of the presenttechnique is a method or a program corresponding to the above-describedtransmitting device of one embodiment of the present technique.

In the transmitting device and method and the program of one embodimentof the present technique, trigger information relating to control of anapplication program run in conjunction with AV content in a receivingdevice is generated, and the generated trigger information istransmitted together with the AV content. Furthermore, downloadinformation relating to download of the AV content transmitted innon-real time is generated, and the generated download information isperiodically transmitted together with the AV content.

According to one embodiment of the present technique, the opportunityfor download reservation of AV content can be widened.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing a configuration example of a broadcastingsystem;

FIG. 2 is a diagram showing a configuration example of a broadcastingdevice;

FIG. 3 is a diagram showing a configuration example of a receivingdevice;

FIG. 4 is a diagram showing the protocol stack of a signal of abroadcast wave;

FIG. 5 is a diagram showing a configuration example of NRT-IT;

FIG. 6 is a state transition diagram of an application program;

FIGS. 7A and 7B are diagrams for explaining an example in which triggerinformation is multiplexed into a transport stream;

FIG. 8 is a diagram showing a concept that trigger information is sotransmitted as to be included in a PCR packet of TS;

FIG. 9 is a flowchart for explaining AV content transmission processing;

FIG. 10 is a flowchart for explaining AV content reception processing;

FIG. 11 is a flowchart for explaining the AV content receptionprocessing;

FIG. 12 is a diagram showing a configuration example of TDO content;

FIG. 13 is a diagram showing a display example of a list of AV contentpermitted to be tentatively reserved; and

FIG. 14 is a diagram showing a configuration example of a computer.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

An embodiment of the present technique will be described below withreference to the drawings.

[Configuration of Broadcasting System]

FIG. 1 is a diagram showing a configuration example of a broadcastingsystem.

A broadcasting system 1 is composed of a broadcasting device 11, areceiving device 13, and a content delivery server 18.

The broadcasting device 11 is set at a broadcasting station. Thebroadcasting device 11 transmits AV content of e.g. show, CM, etc. as adigital television broadcast signal. The digital television broadcastsignal is transmitted as normal broadcasting and NRT broadcasting.

The normal broadcasting is broadcasting premised on viewing in real timein the receiving device 13 into which this broadcast signal is received.Furthermore, the NRT broadcasting is not premised on viewing in realtime. In the NRT broadcasting, there is no need to view AV content atthe broadcast time of the AV content, and the AV content is transmittedas data by a broadcast signal.

Furthermore, the broadcasting device 11 transmits trigger information asa command for ordering execution of data broadcasting content executedin association with the progression of AV content of a show, etc. insuch a manner that the trigger information is included in the digitaltelevision broadcast signal. This trigger information includes, inaddition to information indicating the kind of command, databroadcasting content, i.e. information indicating the acquisition sourceof the data broadcasting content, and so forth. Details of the triggerinformation will be described later.

In addition, the broadcasting device 11 periodically transmitsinformation relating to download of AV content transmitted in non-realtime in the NRT broadcasting (hereinafter, referred to as downloadinformation) together with AV content. As the download information, e.g.the above-described NRT-IT is present. Details thereof will be describedlater.

The digital television broadcast signal transmitted from thebroadcasting device 11 is received by the receiving device 13 by way ofa relay station 12.

The receiving device 13 is set at a user's house for example. If thereceiving device 13 receives a digital television broadcast signal ofthe normal broadcasting, the receiving device 13 makes AV contentobtained from the digital television broadcast signal be displayed on adisplay 13A and viewed.

Furthermore, if download of AV content is reserved, the receiving device13 starts reception of a digital television broadcast signal of the NRTbroadcasting at the broadcast start time of the reserved AV content, andrecords the AV content obtained from the digital television broadcastsignal in a storage 14. Moreover, the receiving device 13 reads out theAV content recorded in the storage 14 and reproduces it to thereby makethe AV content broadcast by the NRT broadcasting be viewed.

In addition, the receiving device 13 is connected to a LAN (Local AreaNetwork) 15 and can connect to the Internet 17 via a router 16. Iftrigger information is obtained from a digital television broadcastsignal, the receiving device 13 connects to the content delivery server18 via the Internet 17 based on the acquisition source of databroadcasting content included in the trigger information and acquiresthe data broadcasting content. The data broadcasting content is notlimited by the method of acquiring it via the Internet 17 and may beacquired from a multiplexed stream obtained by demodulating a digitaltelevision broadcast signal for example.

The receiving device 13 registers tentative reservation of AV contentbased on the acquired data broadcasting content and then registersdefinitive reservation of the tentatively reserved AV content based onthe download information periodically transmitted from the broadcastingdevice 11. Details of download reservation by use of data broadcastingcontent (TDO content to be described later) will be described later.

The content delivery server 18 is set at a broadcasting station or thelike. The content delivery server 18 generates data broadcasting contentfor presenting a list of AV content for which download reservation ispossible in the NRT broadcasting. The content delivery server 18delivers data broadcasting content via the Internet 17 in response to anacquisition request from the receiving device 13.

The broadcasting system 1 is configured in the above-described manner.

The data broadcasting content is realized through running of anapplication program supplied to the receiving device 13 by a computer inthe receiving device 13. Therefore, hereinafter, the data broadcastingcontent will be referred to also as data broadcasting applicationprogram or data broadcasting application.

[Configuration of Broadcasting Device]

FIG. 2 is a diagram showing a configuration example of a broadcastingdevice.

The broadcasting device 11 is composed of a video encoder 31, an audioencoder 32, a multiplexer 33, a trigger generator 34, a downloadinformation generator 35, and a sender 36.

The video encoder 31 encodes the video stream of AV content of a show,etc. input from the previous stage in accordance with a predeterminedencoding system and supplies the encoded video stream obtained as theresult to the multiplexer 33. Examples of the encoding system in thevideo encoder 31 include MPEG2 (Moving Picture Experts Group phase 2)system and H.264 system.

The audio encoder 32 encodes the audio stream corresponding to the videostream input to the video encoder 31 in accordance with a predeterminedencoding system and supplies the encoded audio stream obtained as theresult to the multiplexer 33. Examples of the encoding system in theaudio encoder 32 include AC3 (Audio Code number 3) system and AAC(Advanced Audio Coding) system.

The trigger generator 34 generates trigger information in associationwith the progression of the video stream of AV content input from theprevious stage and supplies it to the multiplexer 33.

The download information generator 35 periodically generates downloadinformation such as NRT-IT based on information relating to AV contentfor which download reservation is possible, and supplies it to themultiplexer 33.

To the multiplexer 33, the encoded video stream from the video encoder31, the encoded audio stream from the audio encoder 32, the triggerinformation from the trigger generator 34, and the download informationfrom the download information generator 35 are supplied.

The multiplexer 33 multiplexes the encoded video stream and the encodedaudio stream and multiplexes also the trigger information to supply themultiplexed stream obtained as the result to the sender 36.Specifically, the multiplexer 33 multiplexes the streams into e.g. TS(transport stream). Alternatively, in consideration of network deliveryof digital television broadcasting, the multiplexer 33 may multiplex thestreams into the ISO base media file format (MP4) suitable for it.

Furthermore, if the download information is supplied from the downloadinformation generator 35, the multiplexer 33 multiplexes the downloadinformation into the multiplexed stream.

The sender 36 sends out the multiplexed stream supplied from themultiplexer 33 as a digital television broadcast signal.

The broadcasting device 11 is configured in the above-described manner.

[Configuration of Receiving Device]

FIG. 3 is a diagram showing a configuration example of the receivingdevice.

The receiving device 13 is composed of a tuner 51, a demultiplexer 52, avideo decoder 53, a video output part 54, an audio decoder 55, an audiooutput part 56, a trigger detector 57, a controller 58, a memory 59, anoperation part 60, a communication I/F 61, a cache memory 62, anapplication engine 63, a download information detector 64, and adownload reservation unit 65.

The tuner 51 receives and demodulates a digital television broadcastsignal corresponding to the channel selected by the user and suppliesthe multiplexed stream obtained as the result to the demultiplexer 52.

The demultiplexer 52 separates the multiplexed stream supplied from thetuner 51 and supplies the separated encoded video stream and encodedaudio stream to the video decoder 53 and the audio decoder 55,respectively. Furthermore, if trigger information or downloadinformation transmitted together with the multiplexed stream isdetected, the demultiplexer 52 supplies the trigger information and thedownload information to the trigger detector 57 and the downloadinformation detector 64, respectively.

The video decoder 53 decodes the encoded video stream from thedemultiplexer 52 and supplies the video signal obtained as the result tothe video output part 54.

The video output part 54 outputs the video signal supplied from thevideo decoder 53 to the subsequent stage (e.g. display 13A).Furthermore, the video output part 54 combines a video signal of a databroadcasting application program (hereinafter, referred to as databroadcasting application) supplied from the application engine 63 andthe video signal supplied from the video decoder 53, and outputs theresulting signal to the subsequent stage.

The audio decoder 55 decodes the encoded audio stream from thedemultiplexer 52 and supplies the audio signal obtained as the result tothe audio output part 56.

The audio output part 56 outputs the audio signal supplied from theaudio decoder 55 to the subsequent stage (e.g. speaker).

The trigger detector 57 detects trigger information from the multiplexedstream separated by the demultiplexer 52 and supplies it to thecontroller 58.

The controller 58 runs a control program recorded in the memory 59 tothereby control the operation of the respective parts of the receivingdevice 13. Furthermore, the controller 58 controls acquisition,activation, event firing, suspension, stop, and so forth of the databroadcasting application based on the trigger information supplied fromthe trigger detector 57.

The operation part 60 accepts various kinds of operation from the userand notifies the controller 58 of an operation signal corresponding toit.

The communication I/F 61 connects to the content delivery server 18 viathe Internet 17 in accordance with control from the application engine63. The application engine 63 acquires a data broadcasting applicationfrom the content delivery server 18 via the communication I/F 61 and theInternet 17 and makes the cache memory 62 retain it in accordance withcontrol from the controller 58.

The application engine 63 reads out and runs the data broadcastingapplication retained in the cache memory 62 in accordance with controlfrom the controller 58.

The download information detector 64 detects download information fromthe multiplexed stream separated by the demultiplexer 52 and supplies itto the controller 58.

The controller 58 analyzes the download information supplied from thedownload information detector 64 and records the analysis result in thememory 59.

The download reservation unit 65 executes processing relating todownload reservation of AV content in accordance with control from thecontroller 58. The download reservation unit 65 is composed of atentative reservation registering part 71 and a definitive reservationregistering part 72.

The tentative reservation registering part 71 registers desired AVcontent selected through running of the data broadcasting application astentative reservation in accordance with control from the controller 58.

If the identifier of AV content included in the download informationanalyzed by the controller 58 is identical to the identifier of AVcontent tentatively reserved by the tentative reservation registeringpart 71, the definitive reservation registering part 72 registers thetentatively reserved AV content as definitive reservation in accordancewith control from the controller 58.

When the present time has become the broadcast start time of the AVcontent for which definitive reservation is registered, the downloadreservation unit 65 controls the tuner 51 to download the AV content ofa predetermined channel. The multiplexed stream received by the tuner 51and demodulated is separated by the demultiplexer 52 and recorded in thestorage 14. If the AV content is acquired from a delivery serverconnected to the Internet 17, when the present time has become thereservation start time of the AV content for which definitivereservation is registered, the download reservation unit 65 controls thecommunication I/F 61 to download the AV content of a predeterminedchannel. The AV content received by the communication I/F 61 is recordedin the storage 14.

If reproduction of AV content recorded in the storage 14 is ordered, thevideo decoder 53 reads out and decodes the encoded video stream recordedin the storage 14 and outputs the video signal obtained as the result tothe subsequent stage via the video output part 54. Furthermore, theaudio decoder 55 reads out and decodes the encoded audio stream recordedin the storage 14 and outputs the audio signal obtained as the result tothe subsequent stage via the audio output part 56.

The receiving device 13 is configured in the above-described manner.

[Details of NRT Broadcasting]

Next, details of the NRT broadcasting will be described below. In theNRT broadcasting, the following two systems exist: a system in which theuser selects individual AV content and thereafter the AV content isreceived and accumulated (hereinafter, referred to as Pull-type NRTbroadcasting); and a system in which the user registers viewing of a setof specified pieces of AV content and thereafter the receiving device 13automatically receives and accumulates these pieces of AV content(hereinafter, referred to as Push-type NRT broadcasting).

Here, the Pull-type NRT broadcasting will be described below.

FIG. 4 is a diagram showing the protocol stack in a signal of abroadcast wave including the NRT broadcasting and the normalbroadcasting.

As shown in FIG. 4, the lowermost hierarchical level is used as PhysicalLayer (physical layer) and the frequency band of the broadcast waveallocated for this channel corresponds to this. The upper hierarchicallevel adjacent to Physical Layer is used as TS (transport stream).

In TS, a packet of the upper hierarchical level is so transmitted as tobe divided into a fixed-length packet called transport packet, and aseries of this transport packet serves as a transport stream. That is,signals transmitted in the frequency band corresponding to one broadcastchannel are all transmitted by the transport packet having headerinformation corresponding to this broadcast channel and so forth.

The upper hierarchical level adjacent to the transport stream is used asSection or PES (Packetized Elementary Stream). For example, datareproduced in real time like AV content of the normal broadcasting istransmitted as a packet of PES. Furthermore, data of file transfer, dataof control information, and so forth are transmitted as a packet ofSection.

As shown in FIG. 4, corresponding to the kind of packet of PES, CaptionCoding, Audio Coding, and Video Coding are defined as the upperhierarchical level of PES. Caption Coding is a packet in which datarelating to a caption of an image is stored. Audio Coding is a packet inwhich audio data is stored. Video Coding is a packet in which image datais stored.

As the upper hierarchical level adjacent to Section, PSIP and PSI aredefined. PSIP (Program and System Information Protocol) is defined as ahierarchical level having VCT, NRT-IT, and so forth. The data of thisPSIP is so configured as to include VCT, NRT-IT, and so forth and isperiodically received by the receiving device 13. PSI (Program SpecificInformation) is defined as a hierarchical level having PAT (ProgramAssociation Table), PMT (Program Map Table), and so forth.

Furthermore, as the upper hierarchical level adjacent to Section, DSM-CC(Digital Storage Media Command and Control) is displayed. DSM-CC is usedas an adaptation layer for transmitting an IP packet on MPEG2-TS of abroadcast stream. DSM-CC is defined as the ISO standard.

As the upper hierarchical level adjacent to DSM-CC, Interactive DataCoding is displayed. Streaming broadcasting is realized by the datastored in Interactive Data Coding, Caption Coding, Audio Coding, andVideo Coding. That is, by receiving these data, a show of the normalbroadcasting can be received and reproduced.

Furthermore, as the upper hierarchical level adjacent to DSM-CC, IP isdisplayed. IP displayed here is the same as IP in the protocol stack ofTCI/IP and an IP packet is specified by the IP address. The NRTbroadcasting is configured by using the IP packet. Of course, the NRTbroadcasting is offered as not communication but broadcasting.Therefore, essentially the protocol stack of TCI/IP, which is acommunication protocol, does not have to be used. However, the IP packetis formally used in download of AV content.

The upper hierarchical level adjacent to IP is used as UDP and FLUTE/ALC(Asynchronous Layered Coding Protocol)/LCT (Layered Coding Transport(Building Block)) is displayed as the upper hierarchical level thereof.Specifically, in the NRT broadcasting, a packet in which a UDP port inTCP/IP communication is specified is transmitted, and a session by FLUTE(File Delivery over Unidirectional Transport) is established forexample. Details of FLUTE are defined as RFC3926.

FIG. 5 is a diagram showing an example of NRT-IT.

The NRT-IT (NRT Information Table) is a table configured withdescriptors for enabling identification of each piece of AV content ofthe NRT broadcasting, broadcast on each channel, in the receiving device13.

As shown in FIG. 5, in the NRT-IT, information relating to download ofeach piece of AV content is described in the description area of eachpiece of AV content. In the example of FIG. 5, for each of Content#1,Content#2, . . . , Content#N, information such as Content ID,Distribution start/end, Content name, and Content URL is described inthe description area thereof.

As Content ID, an ID for identification of the AV content is described.This ID is described with predetermined characters, numerals, etc.

As Distribution start/end, information relating to the delivery scheduleof the AV content is described. As the delivery schedule, informationrepresenting the broadcast start time and broadcast end time of the AVcontent is described. Because the AV content is AV content of the NRTbroadcasting, not the time during which the AV content can be viewed butthe time when download of the AV content should be started and the timewhen the download should be ended are represented by the broadcast starttime and the broadcast end time.

As Content name, information relating to the name of the AV content isdescribed. As this name, the title of the AV content is described by acharacter string, numerals, etc. for example.

As Content URL, information relating to URL (Uniform Resource Locator)for specifying the place where the AV content is disposed is described.

In this manner, Distribution start/end, Content name, and Content URLare described in the description area of the NRT-IT as informationrelating to the AV content identified by Content ID, and the NRT-IT inwhich these pieces of information are described is transmitted asdownload information.

It is also possible to describe e.g. information relating to the versionand expiration date of the AV content and so forth in the descriptionarea of the NRT-IT.

The NRT-IT is configured in the above-described manner.

About this NRT-IT, a description is given in e.g. patent document 1(Japanese Patent Laid-open No. 2011-41242), which is an application bythe present assignee.

[Details of Trigger Information]

Next, details of trigger information will be described below. Thetrigger information is information for controlling a data broadcastingapplication. In this trigger information, commands of e.g. pre-cache,execute, inject event, suspend, and terminate are included.

The pre-cache command (Pre-cache) is a command for ordering acquisitionof a data broadcasting application. Furthermore, the execute command(Execute) is a command for ordering activation of a data broadcastingapplication. Moreover, the inject event command (Inject_event) is acommand for firing an event in the running data broadcastingapplication.

The suspend command (Suspend) is a command for suspending the runningdata broadcasting application. Furthermore, the terminate command(Terminate) is a command for stopping the running data broadcastingapplication.

FIG. 6 is a state transition diagram of a data broadcasting applicationthat operates in the receiving device 13 in response to the respectivecommands of pre-cache, execute, inject event, suspend, and terminate.

As shown in FIG. 6, it is defined that the state of the databroadcasting application has transitioned to one of four kinds ofstates, i.e. stopped state (Stopped), ready state (Ready), active state(Active), and suspended state (Suspended).

The stopped state refers to the state in which the data broadcastingapplication has not yet been acquired into the receiving device 13. Theready state refers to the state in which the data broadcastingapplication has been acquired into the receiving device 13 and is notactivated. The active state refers to the state in which the databroadcasting application is activated and running. The suspended staterefers to the state in which the execution of the data broadcastingapplication is interrupted and information indicating the state of theinterruption timing is retained in a save memory.

When the data broadcasting application has transitioned to the stoppedstate (has not yet been acquired into the receiving device 13),transition to the ready state occurs if trigger information of thepre-cache command is received and the data broadcasting application isacquired in accordance with the pre-cache command.

When the data broadcasting application is in the ready state, transitionto the active state occurs if trigger information of the execute commandis received and the data broadcasting application is activated inaccordance with the execute command.

Furthermore, when the data broadcasting application has transitioned tothe stopped state (has not yet been acquired into the receiving device13), transition to the active state occurs if trigger information of theexecute command is received and the data broadcasting application isacquired and activated in accordance with the execute command.

When the data broadcasting application has transitioned to the activestate, transition to the suspended state occurs if trigger informationof the suspend command is received and the running data broadcastingapplication is interrupted in accordance with the suspend command.

When the data broadcasting application has transitioned to the suspendedstate, transition to the active state occurs if trigger information ofthe execute command is received and the interrupted data broadcastingapplication is resumed in accordance with the execute command.

When the data broadcasting application has transitioned to the readystate, the active state, or the suspended state, transition to thestopped state occurs if trigger information of the terminate command isreceived and the running data broadcasting application is stopped inaccordance with the terminate command.

The state of the data broadcasting application transitions in theabove-described manner.

FIGS. 7A and 7B show the case in which trigger information ismultiplexed into TS.

In this case, the descriptor of the trigger information is defined inthe PMT (Program Map Table) descriptor of the TS as shown in FIG. 7A andthe trigger information is described as shown in FIG. 7B. Specifically,the syntax of the trigger information is described at a positionsubsequent to descriptor_length in FIG. 7B.

The descriptor of the trigger information may be defined in not the PMTdescriptor but e.g. the SIT (selection information table) descriptor.

FIG. 8 shows the concept of the case in which trigger information is sotransmitted as to be disposed in a PCR (Program Clock Reference) packetof the TS of a digital television broadcast signal.

As shown in FIG. 8, the trigger information is not stored in all PCRpackets but stored in the PCR packet only at the proper timing forlinkage to AV content. The PCR packet is a TS packet withadaptation_field in which PCR is stored. The trigger information isstored in transport_private data byte following PCR.

In FIGS. 7A, 7B and FIG. 8, the example in which trigger information isso transmitted as to be multiplexed into TS and the example in whichtrigger information is so transmitted as to be stored in PCR are shown.However, the method for storing and transmitting trigger information isnot limited thereto. As another method, trigger information may beburied in video information itself for example. Furthermore, althoughpre-cache, execute, inject event, suspend, and terminate are describedas one example of the command of trigger information, it is alsopossible to use other commands.

Moreover, about this trigger information, a description is given in e.g.Japanese Patent Application No. 2011-041801 (filing date: Feb. 28,2011), which is an application by the present assignee.

[Flow of AV Content Transmission Processing]

Next, with reference to a flowchart of FIG. 9, AV content transmissionprocessing executed by the broadcasting device 11 will be describedbelow.

In a step S11, the video encoder 31 encodes the video stream of AVcontent of a show, etc. input from the previous stage and supplies theencoded video stream obtained as the result to the multiplexer 33.

In a step S12, the audio encoder 32 encodes an audio stream input fromthe previous stage and supplies the encoded audio stream obtained as theresult to the multiplexer 33.

In a step S13, the trigger generator 34 determines whether or not totransmit trigger information. If it is determined in the step S13 thattrigger information is to be transmitted, the processing proceeds to astep S14.

In the step S14, the trigger generator 34 generates trigger informationassociated with the progression of the video stream of the AV contentinput from the previous stage. On the other hand, if it is determined inthe step S13 that trigger information is not to be transmitted, the stepS14 is skipped and the processing proceeds to a step S15.

In the step S15, the download information generator 35 determineswhether or not to transmit NRT-IT (download information). If it isdetermined in the step S15 that NRT-IT is to be transmitted, theprocessing proceeds to a step S16.

In the step S16, the download information generator 35 generates NRT-ITbased on information relating to AV content for which downloadreservation is possible. On the other hand, if it is determined in thestep S16 that NRT-IT is not to be transmitted, the step S16 is skippedand the processing proceeds to a step S17.

In the step S17, the multiplexer 33 generates a multiplexed stream andsupplies it to the sender 36.

Specifically, in the multiplexer 33, the encoded video stream and theencoded audio stream are multiplexed. In addition, trigger informationis also multiplexed if the trigger information is transmitted. Moreover,NRT-IT is also multiplexed if the NRT-IT is transmitted.

In a step S18, the sender 36 sends out the multiplexed stream suppliedfrom the multiplexer 33 as a digital television broadcast signal.Thereafter, the processing returns to the step S11 and theabove-described subsequent processing is repeated.

In the above-described manner, in the broadcasting device 11, intransmission of AV content, trigger information or NRT-IT is generatedat a predetermined timing and transmitted together with the AV content.

[Flow of AV Content Reception Processing]

Next, with reference to FIG. 10 and FIG. 11, AV content receptionprocessing executed by the receiving device 13 will be described below.

In a step S31, the tuner 51 receives and demodulates a digitaltelevision broadcast signal corresponding to the channel selected by theuser to supply the resulting signal to the demultiplexer 52.

In a step S32, the demultiplexer 52 separates the multiplexed streamfrom the tuner 51 and supplies the separated encoded video stream andencoded audio stream to the video decoder 53 and the audio decoder 55.Furthermore, if trigger information or NRT-IT transmitted together withthe multiplexed stream is detected, the demultiplexer 52 supplies thetrigger information and the NRT-IT to the trigger detector 57 and thedownload information detector 64, respectively.

In a step S33, the video decoder 53 decodes the encoded video streamseparated by the demultiplexer 52 and outputs the video signal obtainedas the result to the display 13A via the video output part 54.

In a step S34, the audio decoder 55 decodes the encoded audio streamseparated by the demultiplexer 52 and outputs the audio signal obtainedas the result to a speaker (not shown) via the audio output part 56.

Thereby, the AV content transmitted from the broadcasting device 11 isreceived and viewed by the user.

In a step S35, the trigger detector 57 determines whether or not triggerinformation is detected from the multiplexed stream separated by thedemultiplexer 52.

If it is determined in the step S35 that trigger information isdetected, the processing proceeds to a step S36. In the step S36, thecontroller 58 analyzes the command indicated by the detected triggerinformation.

In a step S37, the controller 58 determines whether or not the analyzedcommand is Pre-cache. If it is determined in the step S37 that thecommand is Pre-cache, the processing proceeds to a step S38.

In the step S38, the application engine 63 acquires data of TDO contentas the data broadcasting application specified by App_id of this triggerinformation in accordance with control from the controller 58. This TDOcontent is acquired from the content delivery server 18 and retained inthe cache memory 62. App_id is identification information of the databroadcasting application that should be acquired corresponding to thistrigger information.

Subsequently, in a step S39, it is determined whether or not the commandis Execute. For example, if the analyzed command is Pre-cache (“No” ofthe step S39), the processing returns to the step S31 and theabove-described processing is repeated. Subsequently, if triggerinformation is detected (“Yes” of the step S35) again and it isdetermined that the command is Execute (“Yes” of the step S39), theprocessing proceeds to a step S40.

In the step S40, the application engine 63 activates the TDO contentretained in the cache memory 62 as the data broadcasting applicationspecified by App_id in accordance with control from the controller 58.

If program data of the data broadcasting application specified by App_idhas not yet been acquired (does not exist in the cache memory 62), theapplication engine 63 acquires and then activates it. Furthermore, if acurrently-running data broadcasting application exists, the applicationengine 63 stops it and thereafter activates the TDO content.

In a step S41, the application engine 63 determines whether or notinformation relating to download of AV content permitted to betentatively reserved (hereinafter, referred to as tentative reservationdownload information) is included in the TDO content. In the TDOcontent, e.g. tentative reservation download information shown in FIG.12 is described.

FIG. 12 is a diagram showing a configuration example of the TDO content.

As shown in FIG. 12, the TDO content is described based on HTML(HyperText Markup Language).

One or more item elements are described between the start tag and theend tag of the tdo element. The respective item elements are composed ofcontent name element, content ID element, and content url element.

The content name element is an element for describing the name of AVcontent. In the example of FIG. 12, “sportsnews10thApril” is described.

The content ID element is an element for describing the ID to identityAV content. In the example of FIG. 12, “01234567” is described.

The content url element is an element for describing URL to specify theplace where AV content is disposed. In the example of FIG. 12,“http://www.abc.com/NRT/sportsnews/940822.mp4” is described.

In this manner, in the TDO content, ID, name, and URL are described foreach piece of AV content as the tentative reservation downloadinformation for identifying AV content permitted to be tentativelyreserved.

In the example of FIG. 12, the tentative reservation downloadinformation of one piece of AV content is described as a representative.If there are two or more pieces of AV content permitted to betentatively reserved, the tentative reservation download informationcorresponding to that is described based on item element. Furthermore,it is enough that information that enables AV content to be uniquelyidentified is included in the tentative reservation downloadinformation. Therefore, it is not necessary that information of all ofID, name, and URL is included. Furthermore, other pieces ofidentification information may be used. Moreover, tags other than thetags of tdo element and item element may be used.

Referring back to the flowchart of FIG. 10, if it is determined in thestep S41 that tentative reservation download information is included,the processing proceeds to a step S42. In the step S42, the applicationengine 63 supplies the tentative reservation download information to thevideo output part 54 and makes the display 13A display it. For example,a list of AV content permitted to be tentatively reserved, like thatshown in FIG. 13, is displayed on the display 13A.

Referring back to the flowchart of FIG. 10, in a step S43, thecontroller 58 determines whether or not desired AV content is selectedbased on operation of the operation part 60 by the user. If it isdetermined in the step S43 that desired AV content is selected, theprocessing proceeds to a step S44 in FIG. 11.

On the other hand, if it is determined in the step S43 that desired AVcontent is not selected, the processing returns to the step S31 and theabove-described processing is repeated. If trigger information is notdetected (“No” of the step S35) or if tentative reservation downloadinformation is not included in the TDO content (“No” of the step S41),desired AV content is not selected. Thus, the processing returns to thestep S31 and the above-described processing is repeated.

In the step S44 in FIG. 11, the controller 58 determines whether or notNRT-IT periodically transmitted together with AV content is recorded inthe memory 59. If it is determined in the step S44 that NRT-IT is notrecorded, the processing proceeds to a step S45. For example, if theNRT-IT periodically transmitted from the broadcasting device 11 is notreceived due to radio interference and acquisition imperfection(reception miss) in the receiving device 13, old NRT-IT remains recordedin the broadcasting device 11.

In the step S45, the tentative reservation registering part 71 registerstentative reservation of the selected desired content in accordance withcontrol from the controller 58. At this timing, because the reservationis tentative, the tentative reservation registration does not ensurethat download will be surely performed.

Subsequently, in the receiving device 13, if new NRT-IT is transmittedfrom the broadcasting device 11, the NRT-IT is received and detected bythe download information detector 64 (step S46). In a step S47, thecontroller 58 analyzes the newly received NRT-IT.

In a step S48, the controller 58 determines whether or not theidentifier of AV content included in the NRT-IT is identical to theidentifier of the tentatively reserved AV content based on the analysisresult of the newly received NRT-IT.

In this determination processing, for example it is determined whetheror not Content ID described in the NRT-IT (download information) (FIG.5) is identical to the ID of the tentatively reserved AV content,described in the content ID element of the TDO content (tentativereservation download information) (FIG. 12). Furthermore, it is alsopossible to execute the determination processing by use of not onlyContent ID but other pieces of identification information such asContent name and Content URL that are information common to the NRT-ITof FIG. 5 and the TDO content of FIG. 12.

If it is determined in the step S48 that the identifiers are identical,the processing proceeds to a step S49.

In the step S49, the controller 58 determines whether or not thetentatively reserved AV content is downloadable and viewable. If it isdetermined in the step S49 that the tentatively reserved AV content isdownloadable and viewable, the processing proceeds to a step S50.

In the step S50, the definitive reservation registering part 72registers the tentatively reserved AV content as definitive reservationin accordance with control from the controller 58.

Specifically, if NRT-IT is not recorded, temporarily the selecteddesired AV content is registered as tentative reservation. Subsequently,when NRT-IT is newly received, the desired AV content tentativelyreserved is registered as definitive reservation if the identifier of AVcontent included in the NRT-IT is identical to the identifier of thedesired AV content tentatively reserved.

Furthermore, if it is determined in the step S44 that NRT-IT isrecorded, the processing proceeds to the step S47. Subsequently, in thestep S47, the controller 58 analyzes the recorded NRT-IT and determineswhether or not the identifier of AV content included in the NRT-IT isidentical to the identifier of the selected desired AV content based onthe analysis result (step S48). If it is determined in the step S48 thatthe identifiers of AV content are identical, the processing proceeds tothe step S49.

Subsequently, if this AV content is downloadable and viewable (“Yes” ofthe step S49), the definitive reservation registering part 72 registersthe selected desired AV content as definitive reservation in accordancewith control from the controller 58 in the step S50.

That is, if NRT-IT is recorded, tentative reservation of the selecteddesired AV content is not registered and directly this AV content isregistered as definitive reservation if the identifier of this AVcontent is identical to the identifier of AV content included in theNRT-IT.

If it is determined in the step S48 that the identifier of AV contentincluded in the NRT-IT is not identical to the identifier of this AVcontent, the processing proceeds to a step S51. In the step S51, thecontroller 58 determines whether or not the AV content has beententatively reserved. If it is determined in the step S51 that the AVcontent has not been tentatively reserved, the tentative reservationregistering part 71 registers tentative reservation of the AV content inaccordance with control from the controller 58 (step S52). On the otherhand, if it is determined in the step S51 that the AV content has beententatively reserved, the step S52 is skipped and the processingproceeds to a step S53. Subsequently, if new NRT-IT is transmitted fromthe broadcasting device 11, the NRT-IT is received in the receivingdevice 13 (step S53).

If tentative reservation has been registered (step S45), the controller58 determines whether or not a certain time has elapsed after thistentative reservation registration in a step S54. If it is determined inthe step S54 that the certain time has not elapsed, the processingreturns to the step S47, so that the identifier of this AV content iscompared with the identifier of AV content included in newly receivedNRT-IT again.

On the other hand, if it is determined in the step S54 that the certaintime has elapsed, the tentative reservation registration is regarded asinvalid and cancelled and the processing proceeds to a step S55. In thestep S55, the controller 58 controls the application engine 63 and makesthe display 13A display a message indicating that download isimpossible.

Furthermore, also when it is determined in the step S49 that this AVcontent is not downloadable and viewable, such as when the storage 14 isdeficient in the necessary capacity to record the AV content, themessage indicating that download is impossible is displayed similarly.When the capacity deficiency of the storage 14 is resolved, definitivereservation registration may be allowed.

When the processing of the step S55 is ended, the content receptionprocessing of FIG. 10 and FIG. 11 is ended.

That is, if the certain time elapses after tentative reservationregistration or if this AV content is not downloadable and viewable, themessage is displayed and download of the AV content is not performed.

In a step S56, the trigger detector 57 determines whether or not triggerinformation is detected from the multiplexed stream separated by thedemultiplexer 52.

If it is determined in the step S56 that trigger information isdetected, the processing proceeds to a step S57. In the step S57, thecontroller 58 analyzes the command indicated by the detected triggerinformation.

In a step S58, the controller 58 determines whether or not the analyzedcommand is Terminate. If it is determined in the step S58 that thecommand is Terminate, the processing proceeds to a step S59.

In the step S59, if TDO content that is the data broadcastingapplication specified by App_id of this trigger information is running,the application engine 63 stops it. Then the processing proceeds to astep S60.

If trigger information is not detected (“No” of the step S56) or if theanalyzed command is not Terminate (“No” of the step S58), the processingof trigger information is skipped and the processing proceeds to thestep S60. Furthermore, the processing of the end of TDO content based ontrigger information may be executed not only after the end of definitivereservation registration but after the end of tentative reservationregistration or the like for example.

In the step S60, the download reservation unit 65 determines whether ornot the present time has become the broadcast start time of AV contentfor which definitive reservation is registered, and waits until thepresent time becomes the broadcast start time. This broadcast start timeis specified by Distribution start/end described in NRT-IT. If it isdetermined in the step S60 that the present time has become thebroadcast start time, the processing proceeds to a step S61.

In the step S61, the download reservation unit 65 controls the tuner 51to download AV content of a predetermined channel. The multiplexedstream received by the tuner 51 and demodulated is separated by thedemultiplexer 52 and recorded in the storage 14. In the storage 14,information of NRT-IT and so forth is also recorded together with the AVcontent. Furthermore, if two or more pieces of AV content are selected,the processing of the steps S61 and S61 is repeated and all pieces of AVcontent are downloaded. Moreover, if AV content is acquired from adelivery server connected to the Internet 17, the download reservationunit 65 controls the communication I/F 61 to download the AV content ofa predetermined channel and the downloaded AV content is recorded in thestorage 14.

After the end of the download of AV content, in a step S62, thecontroller 58 controls the application engine 63 to display a list ofthe downloaded AV content.

In a step S63, the controller 58 accepts selection of AV content to bereproduced from the displayed list of AV content based on operation ofthe operation part 60 by the user.

If AV content is selected by the user, the video decoder 53 and theaudio decoder 55 read out the encoded video stream and the encoded audiostream, respectively, corresponding to the selected AV content from thestorage 14. Subsequently, the video decoder 53 decodes the encoded videostream and outputs the video signal obtained as the result to thedisplay 13A. Furthermore, the audio decoder 55 decodes the encoded audiostream and outputs the audio signal obtained as the result to thespeaker (not shown).

Thereby, the AV content that is downloaded from the broadcasting device11 and recorded in the storage 14 is reproduced and viewed by the user(step S64).

In the above-described manner, in the receiving device 13, triggerinformation transmitted together with AV content is detected and TDOcontent as a data broadcasting application is acquired based on thedetected trigger information. In addition, desired AV content isselected based on the TDO content. Subsequently, the desired AV contentselected based on the TDO content is registered as tentativereservation, and the tentatively reserved AV content is registered asdefinitive reservation if the identifier of downloadable AV contentincluded in periodically transmitted NRT-IT is identical to theidentifier of the tentatively reserved AV content.

Due to this, even if the NRT-IT retained by the receiving device 13 isnot the latest, tentative reservation of the desired AV content isregistered and the tentative reservation registration is changed todefinitive reservation registration after NRT-IT is newly received.Thus, there is no need to await download reservation until NRT-IT isnewly received. Therefore, loss of the opportunity for downloadreservation of AV content is eliminated and thus download reservation ofAV content in the NRT service can be surely carried out. As a result,the opportunity for the download reservation can be widened.

The above-described broadcasting system 1 of FIG. 1 realizes databroadcasting content that can be in conjunction with AV content in thestate in which the band for broadcasting data broadcasting content isnot set in the broadcasting band of digital television broadcasting likein e.g. the present United States. Furthermore, in the abovedescription, the example in which AV content is broadcast by thebroadcasting device 11 based on a digital television broadcast signal ismainly explained. However, as described above, a dedicated deliveryserver may be provided and AV content may be delivered via the Internet17.

In addition, in the above description, TDO content is explained as adata broadcasting application and the example in which AV contentpermitted to be tentatively reserved is displayed on the display 13A andselected based on the TDO content is explained. However, AV content maybe selected without displaying on the display 13A. For example, throughexecution of TDO content by the controller 58, AV content may beselected based on conditions set in advance and so forth.

Moreover, the TDO content may be not only acquired and activated basedon trigger information but also activated from another piece of TDOcontent. Furthermore, it is explained that the TDO content is describedby HTML. However, the TDO content is configured from JavaScript, JPEGfile, PNG file, etc. besides HTML. In addition, it is also possible toemploy another description language such as BML (Broadcast MarkupLanguage) as the description language of the TDO content.

Moreover, in the above description, the Pull-type NRT broadcasting isexplained. However, the above-described configuration can be similarlyapplied also to the Push-type NRT broadcasting.

[Description of Computer to which the Present Technique is Applied]

The above-described series of processing can be executed by hardware andcan also be executed by software. In the case of executing the series ofprocessing by software, a program configuring the software is installedinto a general-purpose computer or the like.

So, FIG. 14 shows a configuration example of one embodiment of thecomputer into which the program to execute the above-described series ofprocessing is installed.

The program can be recorded in advance in a storing unit 108 such as ahard disc or a ROM (Read Only Memory) 102 incorporated in a computer100.

Alternatively, the program can be stored (recorded) temporarily orpermanently in removable media 111 such as flexible disc, CD-ROM(Compact Disc Read Only Memory), MO (Magneto Optical) disc, DVD (DigitalVersatile Disc), magnetic disc, and semiconductor memory. Such removablemedia 111 can be provided as so-called package software.

Besides the installation from the above-described removable media 111into the computer 100, the program can be wirelessly transferred from adownload site to the computer 100 via an artificial satellite fordigital satellite broadcasting or can be transferred to the computer 100by wiring via a network such as a LAN (Local Area Network) or theInternet. In the computer 100, the thus transferred program can bereceived by a communication unit 109 and installed into the storing unit108.

The computer 100 includes a CPU (Central Processing Unit) 101. To theCPU 101, an input/output interface 105 is connected via a bus 104. Whenan order is input via the input/output interface 105 through operationof an input unit 106 composed of keyboard, mouse, microphone, etc. bythe user and so forth, the CPU 101 runs a program stored in the ROM 102in accordance with it. Alternatively, the CPU 101 loads, in a RAM(Random Access Memory) 103, and runs a program stored in the storingunit 108, a program that is transferred from a satellite or a network tobe received by the communication unit 109 and installed into the storingunit 108, or a program that is read out from the removable media 111mounted in a drive 110 and installed into the storing unit 108. Thereby,the CPU 101 executes processing in accordance with the above-describedflowchart or processing executed based on the configuration of theabove-described block diagram. Subsequently, according to need, forexample the CPU 101 makes the processing result be output from an outputunit 107 composed of LCD (Liquid Crystal Display), speaker, etc. ortransmitted from the communication unit 109 and recorded in the storingunit 108, and so forth, via the input/output interface 105.

Here, in the present specification, the processing steps that describethe program for making a computer execute various kinds of processing donot necessarily need to be processed in a time-series manner along theorder described as the flowchart and encompass also processing executedin parallel or individually (e.g. parallel processing or processing byan object).

Furthermore, the program may be one processed by one computer or may beone subjected to distributed processing by plural computers. Moreover,the program may be one transferred to a distant computer and executed.

In the present specification, the system refers to the whole of a deviceconfigured with plural devices.

Moreover, embodiments of the present technique are not limited to theabove-described embodiment and various changes can be made in such arange as not to depart from the gist of the present technique.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

What is claimed is:
 1. A reception apparatus, comprising: circuitry configured to receive primary AV content; receive trigger information that is associated with the primary AV content; process the primary AV content for display to a user; control execution of an application program, which is programmed to receive from the user a selection of downloadable AV content that is transmitted in a broadcast stream in non-real time, based on the detected trigger information; receive a non-real-time information table (NRT-IT); determine whether the NRT-IT includes download information for the selected downloadable AV content; and schedule download of the selected downloadable AV content from the broadcast stream when the NRT-IT is determined to include the download information for the selected downloadable AV content, wherein the execution of the application program causes the circuitry to display the downloadable AV content for selection by the user to be downloaded from the broadcast stream.
 2. The reception apparatus according to claim 1, wherein the circuitry is configured to: receive a digital television signal that includes the broadcast stream, the broadcast stream including the primary AV content, the trigger information, and the NRT-IT.
 3. The reception apparatus according to claim 1, wherein the download information includes a content identifier, a content name, an expiration time, and delivery timing information of the selected downloadable AV content.
 4. The reception apparatus according to claim 1, wherein the circuitry is configured to: schedule the download of the selected downloadable AV content from the broadcast stream according to delivery timing information included in the download information.
 5. The reception apparatus according to claim 4, wherein the delivery timing information defines a period of time that the selected downloadable AV content is available for download from the broadcast stream.
 6. The reception apparatus according to claim 1, wherein the application program identifies at least one downloadable AV content that is selectable by the user.
 7. A method for receiving AV content, the method comprising: receiving primary AV content; receiving trigger information that is associated with the primary AV content; processing the primary AV content for display to a user; controlling, by circuitry of a reception apparatus, execution of an application program, which is programmed to receive from the user a selection of downloadable AV content that is transmitted in non-real time, based on the detected trigger information; receiving a non-real-time information table (NRT-IT); determining, by the circuitry, whether the NRT-IT includes download information for the selected downloadable AV content; and scheduling, by the circuitry, download of the selected downloadable AV content from the broadcast stream when the NRT-IT is determined to include the download information for the selected downloadable AV content, wherein the execution of the application program causes the circuitry to display the downloadable AV content for selection by the user to be downloaded from the broadcast stream.
 8. The method according to claim 7, further comprising: receiving a digital television signal that includes the broadcast stream, the broadcast stream including the primary AV content, the trigger information, and the NRT-IT.
 9. The method according to claim 7, wherein the download information includes a content identifier, a content name, an expiration time, and delivery timing information of the selected downloadable AV content.
 10. The method according to claim 7, wherein the step of scheduling comprises: scheduling the download of the selected downloadable AV content from the broadcast stream according to delivery timing information included in the download information.
 11. The method according to claim 10, wherein the delivery timing information defines a period of time that the selected downloadable AV content is available for download from the broadcast stream.
 12. The method according to claim 7, wherein the application program identifies at least one downloadable AV content that is selectable by the user.
 13. A non-transitory computer-readable medium storing instructions which, when executed by a computer, cause the computer to perform a method for receiving downloadable AV content, the method comprising: receiving primary AV content; receiving trigger information that is associated with the primary AV content; processing the primary AV content for display to a user; controlling execution of an application program, which is programmed to receive from the user a selection of the downloadable AV content that is transmitted in a broadcast stream in non-real time, based on the detected trigger information; receiving a non-real-time information table (NRT-IT); determining whether the NRT-IT includes download information for the selected downloadable AV content; and scheduling download of the selected downloadable AV content from the broadcast stream when the NRT-IT is determined to include the download information for the selected downloadable AV content, wherein the execution of the application program causes the computer to display the downloadable AV content for selection by the user to be downloaded from the broadcast stream.
 14. The non-transitory computer-readable medium according to claim 13, wherein the method further comprises: receiving a digital television signal that includes the broadcast stream, the broadcast stream including the primary AV content, the trigger information, and the NRT-IT.
 15. The non-transitory computer-readable medium according to claim 13, wherein the download information includes a content identifier, a content name, an expiration time, and delivery timing information of the selected downloadable AV content.
 16. The non-transitory computer-readable medium according to claim 13, wherein the step of scheduling comprises: scheduling the download of the selected downloadable AV content from the broadcast stream according to delivery timing information included in the download information.
 17. The non-transitory computer-readable medium according to claim 16, wherein the delivery timing information defines a period of time that the selected downloadable AV content is available for download from the broadcast stream.
 18. The non-transitory computer-readable medium according to claim 13, wherein the application program identifies at least one downloadable AV content that is selectable by the user.
 19. The reception apparatus according to claim 1, wherein the execution of the application program causes the circuitry to display a plurality of downloadable AV content for selection by the user to be downloaded from the same broadcast stream, the plurality of downloadable AV content including the downloadable AV content. 